Ever have a job you were performing decently, but that still left you wondering every day if a demotion is coming? Adam Warren does. While he's not killing it, or pitching deep into games, his average of just under 5.5 IP/start isn't awful, and not many teams have both 4th and 5th starters beating Warren's 4.50 ERA / 4.15 FIP. But Chris Capuano's return was sure to cost the rotation spot of one guy a decade younger – either Warren or, it turned out, TJ patient Chase Whitley.

Old Man Capuano versus The Kids reminds me of my favorite obscure baseball quote: rookie Sterling Hitchcock's too-bold yet dead-on blasting of the Yankees' impatience with trusting young starters over crappy vets. Hitchcock is a Yankee immortal to me, but for this quote, not his forgettable pitching:

For readers under 40: LaPoint was a great Capuano comp, a soft-tossing lefty the Yankees signed late in an undeservedly long career, given his 94 ERA+ and and 8.4 WAR over nearly 1500 IP. Compare Capuano: ERA+ of 96 that easily could drop below LaPoint's 94; 10 WAR over nearly 1400 IP, but -0.8 from 2013-15.

I've been aboard the Warren-as-starter train since spring: he has (a) better stuff than Whitley and the since-departed Phelps, (b) better control and AAA stats than Mitchell (with no other prospect looking close to ready), and (c) more future than Capuano or Sabathia with about the same low/mid-4s starter ERA prognosis.

Warren is right at Hitchcock's seven-start limit, so maybe LaPoint should make sure Cashman has his new cell number? LaPoint mockery aside, there are gaps in Warren's starting pitching. Going from bullpen to rotation, his K rate plunged from 8.7 to 5.4, and while I haven't seen many of his starts, his velocity seems down by more than a bit. Velocity is just one piece of the puzzle, but when you're a righty without elite control or a killer breaking pitch, the difference between low-90s and mid-90s velocity does matter. So I looked at Warren's, and other pitchers', difference in velocity when working as a reliver versus as a starter.

In 2013-14, when 98% of his appearances were in relief, Warren's four-seamer averaged 93.8 MPH. It's probably more accurate to give him credit for his slightly higher-velocity 2014, when his four-seamer averaged 94.3 MPH and maxed out at 97.3. I remember the first time I saw Warren hit 97 last year; I wondered whether the radar gun was off or whether he'd ordered the A-Rod smoothie boost at Jamba Juice. But it turned out not to be a fluke: his velocity chart by game shows that 96-97 wasn't that uncommon for Warren in 2014.

As a starter in 2015, he's over 2-2.5 MPH lower. His four-seamer is averaging 92.1 and maxing out at 94.4 -- 2.2 and 2.9 MPH lower, respectively, than in 2014. This is consistent with my limited knowledge of his pre-bullpen days as a starter: his one 2012 big-league start averaged 91.7 and maxed out at 93.5; and I remember the similar prospect scouting reports on Warren and Phelps – solid but unspectacuar righty starters who hit only the low 90s.

Basically, when relieving rather than starting, Warren gains much more ability to dial up extra velocity than most other pitchers do – including otherwise similar folks like Phelps. So the situation isn't just (a) "sure, Warren is better relieving than starting, but so is everyone because you need only 2 pitches, don't need to conserve effort, etc." Instead, the situation is (b) "Warren loses a tick more than others do when you move him from pen to rotation."

I'm not suggesting Warren going to the pen now. His 4.50 ERA / 4.15 FIP isn't half-bad, is better than most teams' #4-5 starters, and is better than you can expect from the next available options – Rogers, who's awful, or Mitchell, whose Scranton stats not only are worse than Warren's old AAA stats, but aren't better than Warren's in the bigs now. If a 4-ish FIP is Warren's true level as a starter, then the choice is between a serviceable 4th starter Warren and a strong-but-unelite middle reliever Warren. Unsexy as a #4 starter is, I'd easily choose that over a non-elite reliever; the difference between giving starts to him or to the next dud down the food chain (e.g., Rogers/Mitchell) is bigger than the difference between this or that bullpen righty for several dozen mid-leverage innings.

But Warren's striking difference in velocity and strikeout rate between the pen and the rotation make me think it's a close call what his future is. By the time Tanaka and/or Nova is ready in June, if the Yankees bump Warren rather than Capuano or Sabathia from the rotation, I won't feel like Sterling Hitchcock will be justified in yelling at Dave LaPoint in the old lefties' retirement home where they both live now. I'll feel like it's a plausible call that maybe moving Warren to the rotation saps too much from a talented bullpen arm.